add the possibility to cancel drag-resizing by pressing Esc

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57195 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/headerctrlg.h

@@ -65,6 +65,7 @@ private:
     // event handlers
     void OnPaint(wxPaintEvent& event);
     void OnMouse(wxMouseEvent& event);
+    void OnKeyDown(wxKeyEvent& event);
     void OnCaptureLost(wxMouseCaptureLostEvent& event);
 
     // return the horizontal start position of the given column in physical
@@ -87,6 +88,9 @@ private:
     // column 1 but close enough to the divider separating it from column 0)
     int FindColumnAtPos(int x, bool& onSeparator) const;
 
+    // return true if a drag resizing operation is currently in progress
+    bool IsResizing() const;
+
     // end any drag operation currently in progress (resizing or reordering)
     void EndDragging();
 

src/generic/headerctrlg.cpp

@@ -214,6 +214,11 @@ void wxHeaderCtrl::RefreshColsAfter(unsigned int idx)
 // wxHeaderCtrl dragging
 // ----------------------------------------------------------------------------
 
+bool wxHeaderCtrl::IsResizing() const
+{
+    return m_colBeingResized != COL_NONE;
+}
+
 void wxHeaderCtrl::UpdateResizingMarker(int xPhysical)
 {
     // unfortunately drawing the marker over the parent window doesn't work as
@@ -244,8 +249,7 @@ void wxHeaderCtrl::EndDragging()
 
 void wxHeaderCtrl::EndResizing(int width)
 {
-    wxASSERT_MSG( m_colBeingResized != COL_NONE,
+    wxASSERT_MSG( IsResizing(), "shouldn't be called if we're not resizing" );
-                  "shouldn't be called if we're not resizing" );
 
     EndDragging();
 
@@ -277,6 +281,8 @@ BEGIN_EVENT_TABLE(wxHeaderCtrl, wxHeaderCtrlBase)
     EVT_MOUSE_EVENTS(wxHeaderCtrl::OnMouse)
 
     EVT_MOUSE_CAPTURE_LOST(wxHeaderCtrl::OnCaptureLost)
+
+    EVT_KEY_DOWN(wxHeaderCtrl::OnKeyDown)
 END_EVENT_TABLE()
 
 void wxHeaderCtrl::OnPaint(wxPaintEvent& WXUNUSED(event))
@@ -345,10 +351,23 @@ void wxHeaderCtrl::OnPaint(wxPaintEvent& WXUNUSED(event))
 
 void wxHeaderCtrl::OnCaptureLost(wxMouseCaptureLostEvent& WXUNUSED(event))
 {
-    if ( m_colBeingResized != COL_NONE )
+    if ( IsResizing() )
         EndResizing(-1);
 }
 
+void wxHeaderCtrl::OnKeyDown(wxKeyEvent& event)
+{
+    if ( IsResizing() && event.GetKeyCode() == WXK_ESCAPE )
+    {
+        ReleaseMouse();
+        EndResizing(-1);
+    }
+    else
+    {
+        event.Skip();
+    }
+}
+
 void wxHeaderCtrl::OnMouse(wxMouseEvent& mevent)
 {
     // do this in advance to allow simply returning if we're not interested,
@@ -362,7 +381,7 @@ void wxHeaderCtrl::OnMouse(wxMouseEvent& mevent)
 
     // first deal with the [continuation of any] dragging operations in
     // progress
-    if ( m_colBeingResized != COL_NONE )
+    if ( IsResizing() )
     {
         if ( mevent.LeftUp() )
             EndResizing(xPhysical - GetColStart(m_colBeingResized));